Heat dissipation device

ABSTRACT

A heat dissipation device includes a fin assembly including a plurality of fins and a heat conductive member. Each individual fin includes a main body with one through hole and a sleeve installed in the through hole of the main body. The sleeve has a hole defined therethrough. The heat conductive member has higher heat conductivity than the main bodies of the fins, and is installed into the through hole of the each individual fin via extension through the hole of the sleeve. The main body and the sleeve of the each individual fin are made of different materials so that the sleeve serves as a transition component for facilitating soldering the each individual fin on the heat conductive member and heat conduction from the heat conductive member to the main body of the each individual fin.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat dissipation device for removing heat from a heat-generating device, and more particularly to a heat dissipation device having heat pipes and improved fin structure incorporated therein.

2. Description of Related Art

As computer technology continues to advance, electronic components such as central processing units (CPUs) of computers are being made to provide faster operational speeds and greater functional capabilities. When a CPU operates at high speed in a computer enclosure, its temperature usually increases enormously. It is therefore desirable to dissipate the generated heat of the CPU quickly before damage is caused.

A conventional heat dissipation device for this purpose generally includes a plurality of parallel fins and a heat pipe inserted in the fins. The heat pipe is in thermal engagement with a CPU; thus, heat originating from the CPU is spread through the fins via the heat pipe, and is then dissipated to ambient air.

The fins and the heat pipe are generally made of heat conductive material. In practice, the fins are usually made of aluminum while the heat pipe is usually made of copper when the weight and the cost of the heat dissipation device are taken into consideration. The fins are generally bonded to an outer surface of the heat pipe via soldering. However, aluminum is difficult to solder, and a coat of nickel or cooper is often applied to the fins via plating to ease soldering of the fins. This complicates the manufacturing process of the fins; as a result, production cycle time and the cost of the heat dissipation device are unduly increased.

What is needed, therefore, is a heat dissipation device, which can overcome the above-described disadvantages.

SUMMARY OF THE INVENTION

A heat dissipation device comprises a fin assembly comprising a plurality of fins and a heat conductive member. Each individual fin comprises a main body with one through hole and a sleeve installed in the through hole of the main body. The sleeve has a hole defined therethrough. The heat conductive member has higher heat conductivity than the fin, and is installed into the through hole of the main body via insertion through the hole in the sleeve. The main body and the sleeve of the each individual fin are made of different materials so that the sleeve serves as a transition component for facilitating mounting of each individual fin on the heat conductive member. The sleeve is made of a metal having a heat conductivity higher than that of a metal for forming the main body. Furthermore, the metal for forming the sleeve can be easily soldered to the heat conductive member, which is a heat pipe.

Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an isometric view of a heat dissipation device in accordance with a preferred embodiment of the present invention;

FIG. 2 is an enlarged view of a fin of the heat dissipation device in FIG. 1;

FIG. 3 is an exploded view of the fin in FIG. 2;

FIG. 4 is a cross-sectional view of the fin in FIG. 2 taken from a line III-III in FIG. 2; and

FIG. 5 is similar to FIG. 4, showing that a sleeve in FIG. 4 further comprising a flange.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a heat dissipation device in accordance with a preferred embodiment of the present invention is illustrated. The heat dissipation device generally comprises a fin assembly 10 and two heat conductive members 20, such as two heat pipes inserted into the fin assembly 10. The heat conductive members 20 have higher heat conductivity than the fin assembly 10, and are in thermal engagement with a heat-generating component, such as a CPU (not shown) so as to transfer heat originating from the CPU to the fin assembly 10 to be dissipated to ambient air.

The fin assembly 10 comprises a plurality of individual fins 100 arranged one by one, one of which is shown in FIGS. 2-4. The fin 100 comprises a main body 120 and two sleeves 140 pre-assembled in the main body 120.

The main body 120 generally has a rectangular shape, and comprises a flange 122 perpendicularly extending from a bottom thereof. The main body 120 further comprises two spaced through holes 124 for receiving the heat conductive members 20. An annular wall 126 protrudes from an edge of each through hole 124, and is located at a front side, or a first side of the main body 120. The presence of the annular walls 126 will increase the contacting area between the main body 120 and the heat conductive members 20, thus more effectively transferring heat from the heat conductive members 20 to each individual fin 100. Additionally, the increase of the contacting area between the heat conductive members 20 and the fins 100 will produce greater structural stability. Each main body 120 is made of heat conductive material, such as metal, more particularly aluminum when the cost and the weight of the heat dissipation device are taken into consideration. Since the aluminum solders poorly, the two sleeves 140 made of material, which can be soldered easily and has higher heat conductivity than aluminum, such as copper or silver, are used to improve the bonding strength and heat conduction between the fins 100 and the heat conductive members 20. In other words, the sleeves 140 overlap an inner surface of the through holes 124 of the main body 120 to separate the heat conductive members 20 from the main body 120; as a result, the heat conductive members 20 are in indirect thermal engagement with the fin 100. The detailed structure of the sleeves 140 will be described in the following text.

Each sleeve 140 is generally cylindrical in shape, although it should be understood that the cross-section of the sleeve 140 may be square, rectangular, elliptical or other cross-section as may be selected according to the shapes of the heat conductive members 20 and the through holes 124 of the fins 100. The sleeve 140 generally comprises a hollow body 142 and an annular lip 144 formed at a rear end of the hollow body 142. A hole 146 is defined through the entire sleeve 140 and coaxial with an axis of the hollow body 142. The hole 146 of the sleeve 140 has an inner diameter larger than an outer diameter of the heat conductive member 20, while the hollow body 142 has an outer diameter slightly larger than an inner diameter of the through hole 124 of the main body 120. The lip 144 of the sleeve 140 has a diameter larger than the inner diameter of the through hole 124 of the main body 120 so that the lip 144 serves as a stop or shoulder for limiting the insertion of the sleeve 140 into the through hole 124 of the main body 120.

When the two sleeves 140 are assembled with the main body 120, the hollow bodies 142 of the sleeves 140 are press-fitted into the through holes 124 of the main body 120 with the annular walls 126 tightly surrounding the outer surfaces of the hollow bodies 142 of the sleeves 140. At the same time, the lips 144 of the sleeves 140 are positioned at a rear side, or a second side of the main body 120, overlapping an area in close proximity of the through holes 124 of the main body 120. The lips 144 may be connected to the main body 120 via riveting, punching and other methods. Therefore, the sleeves 140 are firmly installed in the main body 120.

In this embodiment, the lips 144 not only increase the contacting area between the fin 100 and the sleeves 140, but also ensure that the sleeves 140 are firmly installed in the main body 120. For another embodiment, the lips 144 may be only used to increase the contact area between the main body 120 and the sleeves 140.

As described above, the sleeves 140 may be installed in the main body 120 via interference fit, riveting, punching, and so on. Moreover, the sleeves 140 can be firmly installed in the through holes 124 of the main body 120 as a result of a process of synchronous fabrication of the through holes 124 of the main body 120 and the sleeves 140 via punching or piercing. This process comprises following steps:

step (1) providing a first planar plate made of aluminum, which is used for manufacturing the main body 120;

step (2) providing two second planar plates made of copper or silver, which are used for manufacturing the sleeves 140; each second planar plate has a size smaller than that of the first planar plate;

step (3) placing the second planar plates on a predetermined place of the first planar plate, where the through holes 124 of the main body 120 are to be formed;

step (4) piercing the second planar plates and the first planar plate along a direction perpendicular to the first planar plate to create the through holes 124 with the annular walls 126 and the hollow bodies 142 of the sleeves 140, which are in an interference fit with the annular walls 126, meanwhile, parts of the second planar plates that are unchanged form the lips 144.

Therefore, the sleeves 140 are firmly installed in the through holes 124 of the main body 120 at the same time that the through holes 124 with the annular walls 126 and the sleeve 140 are synchronously fabricated.

For further ensuring that sleeves 140 are firmly installed in the through holes 124 of the main body 120, a front end of each sleeve 140 may be shaped so as to create a flange 148 as shown in FIG. 5. The flange 148 is bent outwardly from the front end of the hollow body 142 to abut against a front end of the annular wall 126, thus preventing the sleeve 140 from escaping from the through hole 124 of the main body 120. As a result, the annular wall 126 of the main body 120 is held between the flange 148 and the lip 144 of the sleeve 140.

After the sleeves 140 are assembled into the through holes 124 of the main body 120, the fins 100 are arranged one by one to form the fin assembly 10 with the holes 146 of the sleeves 140 fixed in one fin 100 aligning with the associated holes 146 of the sleeves 140 fixed in the adjacent fins 100. As a result, two passages are defined transversely extending through the fin assembly 10. The heat conductive members 20 are inserted into the associated passages of the fin assembly 10. Finally, the heat conductive members 20 are soldered into the passages by soldering the heat conductive members 20 and the hollow bodies 142 of the sleeves 140 together.

Since the sleeves 140 are positioned between the heat conductive members 20 and the through holes 124 of the main body 120 and serve as transition components, the fins 100 can be firmly bonded to the outer surface of the heat conductive members 20 without being nickel-plated first, and the main body 120 and the heat conductive members 20 may be made of different material. Thus, production cycle time and cost of the heat dissipation device are reduced.

It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention. 

1. A heat dissipation device comprising: a fin assembly comprising a plurality of fins, each individual fin comprising a main body with one through hole and a sleeve installed in the through hole of the main body, the sleeve having a hole defined therethrough; and a heat conductive member being installed into the through hole of the each individual fin via extending through the hole of the sleeve, wherein the main body and the sleeve of the each individual fin are made of different materials so that the sleeve serves as a transition component for facilitating soldering of the each individual fin on the heat conductive member, the material for making the main body having a heat conductivity smaller than that of the material for making the sleeve.
 2. The heat dissipation device as claimed in claim 1, wherein the sleeve is in an interference fit with the through hole.
 3. The heat dissipation device as claimed in claim 1, wherein the sleeve comprises a body inserted into the through hole of the main body.
 4. The heat dissipation device as claimed in claim 3, wherein the sleeve comprises a lip abutting against one side of the main body.
 5. The heat dissipation device as claimed in claim 4, wherein the main body comprises a wall protruding from an edge of the through hole, and an outer surface of the sleeve is in an interference fit with the wall.
 6. The heat dissipation device as claimed in claim 5, wherein the lip of the sleeve is formed at one end of the sleeve, and a flange is formed at opposite end of the sleeve, the flange of the sleeve engaging with a free end of the wall of the main body so that the main body is held between the flange and the lip of the sleeve.
 7. The heat dissipation device as claimed in claim 1, wherein the heat conductive member comprises a heat pipe adapted for thermally engaging with a heat-generating component.
 8. The heat dissipation device as claimed in claim 1, wherein the main body is made of aluminum, while the sleeve is made of one of copper and silver.
 9. The heat dissipation device as claimed in claim 1, wherein the hole in the sleeve has an inner diameter larger than an outer diameter of the heat conductive member and the sleeve has an outer diameter larger than an inner diameter of the through hole of the main body.
 10. The heat dissipation device as claimed in claim 1, wherein the heat conductive member and the main body of the each individual fin are separated from each other by the sleeve of the each individual fin so that the heat conductive member is in indirect thermal engagement with the main body of the each individual fin.
 11. A fin assembly comprising: a plurality of fins, each individual fin comprising: a main body with one through hole; and a sleeve assembled in the through hole of the main body, the sleeve overlapping an inner surface of the through hole of the main body; wherein the main body and the sleeve are made of different materials so that the sleeve serves as a transition component between the each individual fin and a heat conductive member extending through the through hole of the main body.
 12. The fin assembly as claimed in claim 1, wherein the main body comprises a wall protruding from an edge of the through hole, the wall enclosing an outer surface of the sleeve.
 13. The fin assembly as claimed in claim 12, wherein the sleeve comprises a body enclosed by the wall of the main body, and a lip abutting against one side of the main body.
 14. The fin assembly as claimed in claim 13, wherein the body and the lip of the sleeve are located on opposite sides of the main body.
 15. The fin assembly as claimed in claim 13, wherein the sleeve comprises a flange engaging with a free end of the wall of the main body so that the main body is held between the flange and the lip of the sleeve.
 16. The fin assembly as claimed in claim 1, wherein the main body is made of aluminum, while the sleeve is made of one of copper and silver.
 17. The fin assembly as claimed in claim 11, wherein the material for forming the sleeve has a heat conductivity higher than that of the material for forming the main body of the each individual fin.
 18. The fin assembly as claimed in claim 17, wherein the material for forming the sleeve can be more easily soldered to the heat conductive member than the material for forming the main body of the each individual fin.
 19. The fin assembly as claimed in claim 11, wherein the material for forming the sleeve can be more easily soldered to the heat conductive member than the material for forming the main body of the each individual fin.
 20. The fin assembly as claimed in claim 19, wherein the material for forming the sleeve is copper and the heat conductive member is a heat pipe. 